From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LD3RI-0002eB-BO for qemu-devel@nongnu.org; Wed, 17 Dec 2008 15:56:16 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LD3RG-0002dR-V9 for qemu-devel@nongnu.org; Wed, 17 Dec 2008 15:56:15 -0500 Received: from [199.232.76.173] (port=37427 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LD3RG-0002dH-O0 for qemu-devel@nongnu.org; Wed, 17 Dec 2008 15:56:14 -0500 Received: from mail-qy0-f20.google.com ([209.85.221.20]:41750) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LD3RG-00032y-4u for qemu-devel@nongnu.org; Wed, 17 Dec 2008 15:56:14 -0500 Received: by qyk13 with SMTP id 13so164827qyk.10 for ; Wed, 17 Dec 2008 12:56:12 -0800 (PST) Message-ID: <49496765.8000404@codemonkey.ws> Date: Wed, 17 Dec 2008 14:56:05 -0600 From: Anthony Liguori MIME-Version: 1.0 References: <1229546822-11972-1-git-send-email-glommer@redhat.com> <1229546822-11972-2-git-send-email-glommer@redhat.com> <1229546822-11972-3-git-send-email-glommer@redhat.com> <1229546822-11972-4-git-send-email-glommer@redhat.com> In-Reply-To: <1229546822-11972-4-git-send-email-glommer@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH 3/5] replace cpu_physical_memory_rw Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Glauber Costa Cc: stefano.stabellini@eu.citrix.com, Ian.Jackson@eu.citrix.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, avi@redhat.com Glauber Costa wrote: > This patch introduces a kvm version of cpu_physical_memory_rw. > The main motivation is to bypass tcg version, which contains > tcg-specific code, as well as data structures not used by kvm, > such as l1_phys_map. > > In this patch, I'm using a runtime selection of which function > to call, but the mid-term goal is to use function pointers in > a way very close to which QEMUAccel used to be. > > Signed-off-by: Glauber Costa > --- > exec.c | 13 +++++++++++-- > kvm-all.c | 39 +++++++++++++++++++++++++++++++++++---- > kvm.h | 2 ++ > 3 files changed, 48 insertions(+), 6 deletions(-) > > diff --git a/exec.c b/exec.c > index 04eadfe..d5c88b1 100644 > --- a/exec.c > +++ b/exec.c > @@ -2938,8 +2938,8 @@ int cpu_physical_memory_do_io(target_phys_addr_t addr, uint8_t *buf, int l, int > > + > +void kvm_cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf, > + int len, int is_write) > +{ > + KVMSlot *mem; > + KVMState *s = kvm_state; > + int l; > + > + mem = kvm_lookup_slot(s, addr); > + if (!mem) > + return; > + > + if ((mem->phys_offset & ~TARGET_PAGE_MASK) >= TLB_MMIO) { > + l = 0; > + while (len > l) > + l += cpu_physical_memory_do_io(addr + l, buf + l, len - l, is_write, mem->phys_offset); > + } else { > + uint8_t *uaddr = phys_ram_base + mem->phys_offset + (addr - mem->start_addr); > + if (!is_write) > + memcpy(buf, uaddr, len); > + else > + memcpy(uaddr, buf, len); > + } > +} > I think this is a bit optimistic. It assumes addr..len fits entirely within a slot. That's not necessarily the case though. I think you should probably limit len to whatever is left in the slot, then if necessary, (tail) recursively call kvm_cpu_physical_memory_rw. Regards, Anthony Liguori